I just bought a Used 2005 TZ25DA with 10LA FEL and 225 hours. I have gone over the machine and changed the engine oil/filter, air filters/ hydraulic oil & filter and HST filter and lube all found fittings. Before I did all this I had noticed that low range reverse was extremely slow and lacked power (had to use empty bucket to help push back up a small hill). Forward, Hi or Low, was fine and had plenty of power. Now with fluids all changed and up to snuff, I have virtually no speed at all in Low Range reverse (have not gotten into an up hill case to check power) and the tractor will not go anywhere in reverse Hi. Forward is fine in Hi and Lo. Any suggestions?

Replying to my own post.

An update to the problem description. I failed to mention that the tractor RPM's were up (around 3,000) which I had learned early on was needed with the HST transmission.

The problem has now been corrected!

After reading other posts referencing linkage problems, I went back and looked at the linkage as I worked the pedals. I noticed that the support plate (Item 14 on Parts Diagram 03.09 HST Control; Pedals, Link) had play in it when I moved the reverse pedal. With closer examination I noticed that one of the two mounting bolts (item 13 in the same parts diagram) was loose. In trying to tighten it I found out that someone had tried to put on a coarse thread 8mm nut on a fine thread 8mm bolt. Replaced this arrangement, tightened them up and the unit backs up like a dream.

Same thing happened to me, I lost reverse but still had forward, then discovered that one mounting bolt was missing and the other acting like a pivot. Easy fix, thankfully. Now my hydraulic filter (not the HST filter) just burst today and dumped a lot of oil on the ground. I understand that in cold temps (-25C today) these filters are prone to bursting.